Diagnostic algorithm for determining primary tumor sites using peritoneal fluid
Fig 4
Typical immunocytochemistry patterns based on primary origins.
Three parameters, three-dimensional (3D) clusters and dual staining for CK7 and PAX8, can identify the primary origin. Each panel represents different patterns of dual staining. (A) Stomach cancer: most cells are scattered and show CK7+/PAX8- immunoprofile. (B) Gastrointestinal tract, including stomach and pancreatobiliary tract cancer: mostly small 3D cluster with scattered cells are CK7+/PAX8-. (C and D) Female genital tract, including ovarian cancer: large 3D cluster with scattered cells are CK7+/PAX8+. There is positive staining for nuclear PAX8-DAB in the cell with the large cytoplasm.